Machine for making concrete slabs or plates.



C. L. NORTON.

MACHINE FOR MAKING CONCRETE SLABS 0R PLATES.

APPLICATIGN FILED vJULY 20, 19H.

PatentedfMay 25, 191.5.

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UNirRD sTArEs PATENT. onirica.

CHARLES L. NORTON, or HUDSON, NRW HAMPSHIRE, ASSIGNOR To AsBEs'rOs sHINciLEy COMPANY, or NAsHUA, NRW HAMPSHIRE, A. CORPORATION or NEW YORK.

.MACHINE FOR MAKING CONCRETE sLABs OR PLATES.v

Application mea July 2O, 1914. serial N01 51;855.

T0 all whom t may concern .y

Be it known that I, CHARLES L. NORTON,

la citizen of the United States, and resident of Hudson, in the county of lHillsboro and State of New Hampshire, have invented new and usefulImprovements in Machines for Making Concrete Slabs or Plates, of which the following is a specification. n

This invention relates to the art of continuous production of 'concrete slabs or plates, and is an improvement upon the art as represented by United States Letters Patent No. 979,548, datedDecember 2i, 1910.

The object of the invention is to insure a greater regularityof Aproduct than has heretofore beenlobtained, and to obviatc the necessity of the nice adjustments of machine and materials, and the close vigilance, which the employment of the machine described in the ,said` patent entailed. That machine (and the method practised by itl'w as char-l acterized chiefly by compressinga band of concrete-material in two distinct stages, first dry, and then wet, and so far as experience has taughtthose who practise this art, this characteristic two-stage method Ofprocedure cannot safely or practically be dispensed with, ifin'deed-it is dispensable at all.

The specific mode by which the separation of the wet and dry regions of the plate making machine of the. said patent was accomplished, lay in the employment of two separate and distinct belt conveyers, one of which took the dry material, and sustained it during the dry-pressing, the other .of which received the dry-pressed material from the first, conveyed it and sustained itwhile it was being first wetted and then wet-pressed, finally delivering it, severed into plates. The transfer of dry material from the dry belt to the wet belt involved the rather delicate operation of shoving the dry-pressed band of material across a smooth metal bridge, placed between the adjacent ends of the two belts. Under the supervision of skilled attendants this operation could be, and was, performed successfully and on a commercial scale, but any relaxation of vigilance on the part of these attendants, Or anychange for the worse-- in respect to skill and knowledgein the attendants, rendered the machine liable to slips in between, and detracted from the uniform excellence desired in the product. Specifically, therefore, the Object of this in- Specification of LcttersPatent.

Patented May 25, 1915.

vention (which has been attained in commercial practice) is, to dispense with the physicalseparationof the two vconveyers and therefore to dispense with the bridge (which occasionally, under the stress lof industrial operation of the niachine'of the Patent No.

0791548 became truly a "bridge of sighs while conserving the values of separation of the dry-pressing rgion from the wet-pressing region. In brief, this is accomplished by the employmentv of a singie endless belt conveyer, which carries the material through the dry-press rolls, to the water supply, through the wet-"pres:` rolls, delivers the product, returns, is deprived of all undesirable moisture, and again engages the continuously supplied dry material.

In the drawings hereto annexed, which illustrate thc invention,` Figurel is a diagrammatic side elevation of a machine embod ying the invention, and`Fig. 2 is a detail,

showingthe mechanical scraper for cleansing the couveyer and removingpart of its moist-ure.

The numeral 1 represents the con"eye1,

`which is an endless belt, preferably of canvas and rubber, A is agliopper to deliver' concrete-material to the receiving end of the conveyer, 2, Q, are the dry-press rolls, 3, 3,

the wet press rolls, l a rotating cutter frame which grooves the band of concrete-material laterally, to facilitate its subsequent sepavration into plates, 5 is the water-sprinkler, G

the delivery roll, and L a rotating brush or scraper frame, armed with rubber squeegees and rotated so as to wipe solid and liquid materials from the conveyer 1 during its return movement toward the hopper A.

B is a conveyer for surplus material, which is scraped from the conVeyer l, first by a right and left pitched worm 7 then by a rotary brush 8, and finally by side scrapers 9, Of which there is one at each side of the conveyer 1. Plates 11 (one at each side of the conveyer 1) guide surplus material to the return-conveyer li. The conveyor B also receives the spill from the hopper A, through the chute F, and delivers all the surplus material to the chute C, Which passes the material to thehoist D, which in turn delivers it again, through pipe I and chute C to the top of the hopper A. Meanwhile fresh supply, delivered by another hoist (not shown) passes through pipe E to hopper A.. The mechanism for handling the niaterialnis so arranged and the supply so regulated, that there is a continual spill from the top of the hopper A., and also from the receiving end of the conveyer 1. Since the concrete-material contains finelyfcomminuted cement, a thick dust cloud is progion in suitable condition for the dry-pressing part of the cycle, it is so manipulated and treated on its return from the delivery roll 6to the hopper A, that practically all moisture is eliminated from it. This elimination of moisture may be accomplished in divers ways that will occur to the engineer or machine designer; the injunction to rid the conveyer of moisturewillsuggest heaters, fanningy devices,"dryair currents, drying rolls, drying chambers, and what not, any of which will perform the prescribed function. Preferably, 1iowever, t`he restoration of the convejer to proper condition for the pre- "--l-iminary dry-pressing of the material, is

carried out in the manner here illustrated, towit:

' The rotating squeegee scraper L, striking the surface of the conveyer `1, beats off ak large part of the adhering moisture-'and incidentally any fragments of solid material tliat may have remained upon it, but leaves the surface still somewhat damp to the touch. In this\condition the conveyerpasses into the cloud of cement-dust where the vpowdery surface which is as if dusted with talc-powder and in the best possible condition for the reception and dry-pressing of the material received from the hopper A.

By themeans above described, the band of concrete-material carried by the conveyer l is subjected tol no such precarious treatment as was involved by the employment of the physically separate conveyers of Patent No. 979,548 and vthe intervening bridge, while the. distinction'between Wet andr dry regions isI preserved.

Vhat I claim, and desire to secure by Letters Patent, is:

1. In a machine of thel character described, the combination of an endless belt convcyer, means to supply material to the conveyer, dry-press rolls, *wetting devices, Wet-press rolls, a delivery roll, and means to conne a cloud of cement-dust about the conveyer, between the delivery roll and the material-supplying means.

'2. In a machine of the chai'acter de-i scribed, the combination of an endless belt conveyer, means tov supply material' to the conveyer, dry-press rolls, wetting devices,

wet-press`rolls, a delivery roll, a mechaniy cal device for removing moisture from the conveyer,l and means to confine a cloud of cement-dust 'about the conveyer, between the delivery roll and the materi,al-supplyingA CHARLES L. NORTON. I/Vitnesses:

CHARLES D. WOODBERRY, J osErHiNE H. RYAN. 

